blowers of aircon running uneven

[THAIPHUKET]

drives me nuts, as if wind gusts are being caught in the ventilators, but no leaf moving. One of them is brand new, Dainkin.

The main unit is installed so that no compressor sound can be heard. Any guesses?

[Naam]

fluctuation in Hertz (cycles) main cause. have a similar problem, measured 46-52Hz. no way to compensate... except if Crossy proves that i am wrong with my assumption.

[THAIPHUKET]

I thought of that possibility too, I guess these variations 46-52 Hz would not be noticeable in any other user, such as light bulbs? Swings too fast ? Also assume that at night it should occur more often, but it does during the day as well.

Curious to hear more.

[Crossy]

Our Samsung whistles like that when the filters are blocked, worth a look to see if something has been left behind.

[PeterSmiles]

One of them is brand new, Dainkin.

That's what you get with those copy Daikin's

[cdmtdm]

was the indoor unit running while you renovated the house of someone was sanding walls etc ? check the filters but also check the indoor fan blower that it is not full of dust and crap ... that will set the blower off balance for sure ... if it was a variation in hz you would notice i think with other electrical items ...

[h90]

Our Samsung whistles like that when the filters are blocked, worth a look to see if something has been left behind.

We had the aircon blow only on half the side.

Reason that rotating wheel that blows was dirty...well it was dirty but I didn't think it reduce the airflow to zero.

It is relative easy to remove and clean --->everything OK

[Pib]

I doubt the line frequency is changing very much...a few months ago I got one of those wattmeter thingies where you can measure/monitor all kinds of electric usage things and even though the readout of line frequency is only one decimal point (i.e., 50.0, 49.9, 50,1), the readout never changed from 50.0 here in western Bangkok. I've checked a few times with a multimeter which has frequency measurement capability but with two decimal point resolution and once again it was almost exactly on 50Hz. Even if it was changing a few hertz I not sure that would really be noticeable.

From your OP, I'm note sure if you are talking speed-like sounds on your inside unit (evaporator) or outside unit (condenser/compressor), but if talking the inside unit a dirty roller/squirrel cage blower can cause a speed varying sound...plus make the air output uneven across the bent outlet...the air coming out of the vent outlet should be pretty even all the way across it. This is what happens on a couple of my heavily used York evaporator units if I don't clean the blower fan at least every 9 months or so. As long as the directional vent louvers are set to blow straight out and your filters are clean, it could be a dirty blower fan.

[h90]

I doubt the line frequency is changing very much...a few months ago I got one of those wattmeter thingies where you can measure/monitor all kinds of electric usage things and even though the readout of line frequency is only one decimal point (i.e., 50.0, 49.9, 50,1), the readout never changed from 50.0 here in western Bangkok. I've checked a few times with a multimeter which has frequency measurement capability but with two decimal point resolution and once again it was almost exactly on 50Hz. Even if it was changing a few hertz I not sure that would really be noticeable.

From your OP, I'm note sure if you are talking speed-like sounds on your inside unit (evaporator) or outside unit (condenser/compressor), but if talking the inside unit a dirty roller/squirrel cage blower can cause a speed varying sound...plus make the air output uneven across the bent outlet...the air coming out of the vent outlet should be pretty even all the way across it. This is what happens on a couple of my heavily used York evaporator units if I don't clean the blower fan at least every 9 months or so. As long as the directional vent louvers are set to blow straight out and your filters are clean, it could be a dirty blower fan.

I am no specialist but if the 50 Hz vary than all the turbines in Thailand must run slower/faster.

[THAIPHUKET]

it is the inside part, machines are regularly cleaned. Blower off balance could be one reason, but on 2 machines at the same time? Less likely.It sounds to my ear as if motor is too weak to keep a steady speed, like uphill and downhill, not enough Watt? Layman speaking,

[h90]

it is the inside part, machines are regularly cleaned. Blower off balance could be one reason, but on 2 machines at the same time? Less likely.It sounds to my ear as if motor is too weak to keep a steady speed, like uphill and downhill, not enough Watt? Layman speaking,

regularly cleaned?

did you look yourself if it is clean?

By the way, other idea.....

Open it, remove the filter, wait 5-6 hour or longer (turned off) let it run.

Does it blow now?

If the freeze sensor is broken, or maybe it is enough to have it charged with the wrong pressure, it freezes and no air can move.

It happened on 2 aircons here even with the freeze sensor installed (broken, wrong one???)

[THAIPHUKET]

Airflow is 100% free, it´s only the noise from the blower which sounds like an uneven running cylinder

[h90]

Airflow is 100% free, it´s only the noise from the blower which sounds like an uneven running cylinder

some dirt sticking to the cylinder?

Mine had a lot very sticky dirt on it, if someone would clean it and let a little dirt somewhere than it wouldn't be balanced anymore and vibrate.

Second idea: it is fixed with a screw on a shaft, if the screw is loose it might vibrate (but I don't think that it is the reason).

Third idea it isn't the cylinder some other part close to it vibrate (because someone didn't fit it together perfect after cleaning).

I would take it apart yourself and have a look.

If they aren't mounted to close the ceiling it is easy to take them apart and put them together again, once you know all the tricks. If you have 2 that are the same model you can always look on the second if you are unsure how to put it together again.

(since I take ours apart I don't let anyone service them anymore.....everywhere poor job, missing screws, broken plastic etc etc

[cdmtdm]

clean the blowers yourself , the ac guys wont do it for sure.... or the evap coil may also be blocked m easy to clean both ...

[wayned]

If the unit has just been installed, I would check the electrical connection, especially if they spliced into an existing wire. If the connection is loose and arcing it could cause your problem and would also be a fire hazard.

[T_Dog]

Are you sure its just not the controller changing the speed automatically as it comes to the set temperature? The Daiken units seem to change pretty slowly when in the automatic fan mode. If not that, your line voltage may be varying as loads such as water heaters come on line. Would not be the line frequency changing as the entire grid has to be at exactly 50 Hz.

[Naam]

I thought of that possibility too, I guess these variations 46-52 Hz would not be noticeable in any other user, such as light bulbs? Swings too fast ? Also assume that at night it should occur more often, but it does during the day as well.

Curious to hear more.

you notice it with motors and electric clocks. both are driven by cycles. my measurements are from the read-out of two cycle converters which i use to adjust the speed of a whole-house fan and a roof fan which exhausts the attic.